Enlightenment consists not merely in the seeing of luminous shapes and visions, but in making the darkness visible. (Carl G Jung)
One does not become enlightened by imagining figures of light, but by making the darkness conscious. (Carl G Jung)
In his poem titled The Light of Mind (02 Sep 2011), John Weeren nicely catches something intrinsic to the human mind:
the light of mind
asks how to create shadows —
only darkness knows
Best I not say more.